1. a) The owner or official custodian, or an authorized delegate, must collect water samples for each application of copper sulfate, a copper sulfate-based product, or a copper sulfate chemical aid. Water samples must be collected at the locations and times established in this subsection (a).

   1. 1) From the raw water intake, one sample must be collected before treatment.

   2. 2) From the entry point to the distribution system, one sample must be collected:

      1. A) approximately 24 hours following the copper sulfate treatment; and
      2. B) approximately 48 hours following the copper sulfate treatment.
2. b) The sample results must demonstrate that concentrations of copper do not pose a high health risk to water consumers in compliance with 35 Ill. Adm. Code 611.350(c)(2).

(Source: Amended at 47 Ill. Reg. 7449, effective May 16, 2023)